Abstract: Methods, systems, and devices for wireless communications are described. The described techniques support blind common phase error (CPE) and residual carrier frequency offset mitigation. Generally, the described techniques provide for blind CPE mitigation at a receiving device without a phase tracking reference signal (PTRS) associated with less overhead and improved performance as compared to use of a PTRS to mitigate CPE. A receiving device may receive a shared channel message in a scheduled shared channel allocation in accordance with a PTRS configuration that omits a PTRS allocation based on a capability of the receiving device to apply blind CPE mitigation for shared channel receptions. In some examples, with a single DMRS symbol allocation, blind CPE mitigation for each subsequent data symbol of a shared channel message may be based on the blind CPE estimation for the previous symbol, which may enable robust mitigation of a residual carrier frequency offset.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) receives control signaling from the base station indicating a set of transmission mode indicators or transmission mode options and a set of demodulation reference signal (DMRS) configurations for every transmission mode from a set of transmission modes. The base station transmits additional control signaling to dynamically indicate a transmission mode or a combination of transmission mode indicators and DMRS configuration parameters to signal the transmission mode and one or more associated DMRS configurations. The UE identifies a DMRS configuration and a transmission mode based on the additional control signaling. The UE receives one or more DMRSs from multiple transmission reception points (TRPs) based on the joint/disjoint DMRS and transmission mode signaling. The UE receives one or more data messages from the TRPs based on the transmission mode indication and based on the received DMRSs.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may transmit a request, for an uplink transmission or a downlink transmission, for data aided phase tracking reference signals (PT-RSs) on multiple layers of a communication link; and communicate the uplink transmission or the downlink transmission based at least in part on the request. Numerous other aspects are provided.

Abstract: This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for determining a constellation configuration for an amplitude phase shift keying (APSK) modulation scheme. The constellation configuration may be based on communication impairment information that is indicative of at least one communication impairment expected to impair a single-carrier waveform communication. Examples of communication impairments may include additive white gaussian noise (AWGN), phase noise, non-linear distortion, or any combination thereof, among other examples. Examples of a constellation configuration may include a quantity of rings in a constellation pattern associated with the APSK modulation scheme, a quantity of constellation points associated the rings, a ring radius associated with one or more rings, a phase offset to one or more rings, and a mapping of data bits to one or more constellation points, among other examples.

Abstract: A base station may configure a user equipment (UE) with a subset of reference signal (RS) configurations among a set of RS configurations, and transmit a plurality of RSs based on the subset of RS configurations. The RS may be a demodulation RS (DMRS). The plurality of RSs may be configured to span each of the plurality of resource elements (REs) in the active bandwidth part (BWP). The UE may receive the plurality of RSs based on the subset of RS configurations and perform a spur detection based on the plurality of RSs received based on the subset of RS configurations. Each RS configuration of the set of RS configurations may be associated with at least one of the subset of RS configurations that is associated with the plurality of RSs spanning each of the plurality of REs in the active BWP.

Abstract: A transmitting device may select frequency domain resources for an alert transmission based on a severity level of the alert transmission. The transmitting device may determine a severity level of an alert transmission to be transmitted on one or more available channels. The transmitting device may determine a presence of one or more systems configured to transmit on one or more neighbor channels of the one or more available channels. The transmitting device may select, for the alert transmission, frequency domain resources within the one or more available channels based on the presence of the one or more systems and the severity level. The frequency domain resources for a highest severity level transmission are spaced further apart from the one or more neighbor channels in the frequency domain than resources for a lower severity level transmission. The transmitting device may transmit the alert transmission on the frequency domain resources.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication that the UE supports communications having a first transport block applied to demodulation reference signals (DMRSs) and a second transport block applied to data symbols of a data channel. The UE may transmit an uplink communication or receiving a downlink communication having the first transport block applied to the DMRSs and the second transport block applied to the data symbols of the data channel. Numerous other aspects are provided.

Abstract: Wireless communication techniques for supporting, selecting, and using multiple waveforms and/or multiple decoders for downlink wireless communication are discussed. A UE may transmit to a base station a request to use a first waveform during a first time period for downlink wireless communication. The UE may receive from the base station a response to the request that includes an indication of a selected waveform to use during the first time period for the downlink wireless communication.

Abstract: In a wireless communication system, dynamic changes of a code block (CB) to resource element (RE) mapping type may improve decoding performance in some scenarios. A user equipment may provide an indication of a preferred CB mapping type. A base station may transmit a physical downlink shared channel (PDSCH) based on a first dynamic CB mapping type in one or more slots. A UE may receive the PDSCH and determine a second CB mapping type that is preferred by the UE based on a metric. The UE may transmit an indicator of the second CB mapping type, for example, as a one-bit or two-bit indicator, which may be coupled with a channel state information (CSI) report or signaled in uplink control information (UCI) independently from a CSI report. The base station may consider the indicator when selecting a new dynamic CB mapping type for the UE.

Abstract: A method of wireless communications by a user equipment (UE) includes transmitting a wakeup message to awaken a base station from a sleep mode. The method also includes communicating with the base station after the base station awakens. A method of wireless communications by a base station includes entering a sleep mode when no user equipments (UEs) are connected to the base station. The method also includes receiving a signal from a UE to awaken from the sleep mode. The method further includes resuming signal transmissions after waking up from the sleep mode.

Abstract: Aspects described herein relate to converting, by applying a non-linear function, a symbol indicating first data into an analog signal for transmitting to a network node, wherein applying the non-linear function indicates second data, separate from first data, and transmitting the analog signal to the network node. Additional aspects relate to receiving an analog signal from a user equipment (UE), and estimating a non-linear function applied to the analog signal in converting a symbol indicating first data into the analog signal, wherein estimating the non-linear function indicates second data, separate from first data.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a message from a network entity indicating a first set of configuration parameters for tracking reference signals (TRSs) specific to the UE. The UE may monitor for one or more TRSs according to the first set of configuration parameters and during a first time interval. The UE may receive a layer-1 (L1) signal or a layer-2 (L2) signal from the network entity indicating a second set of configuration parameters for the TRSs specific to the UE that are different from the first set of configuration parameters. The UE may transmit an acknowledgement message to the network entity indicating the UE received the L1 signal or the L2 signal. During a second time interval subsequent to the first time interval, the UE may monitor for additional TRSs according to the second set of configuration parameters.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may transmit, to a user equipment (UE), a first demodulation reference signal for each of one or more sub-bands and configured in accordance with a first one or more demodulation reference signal configurations. The UE may select a second demodulation reference signal configuration from a respective set of second demodulation reference signal configurations for each of the one or more sub-bands and may transmit an indication of the second demodulation reference signal configuration for each of the one or more sub-bands. The base station may receive the indication and may transmit, to the UE, a second demodulation reference signal for each of the one or more sub-bands and configured in accordance with the second demodulation reference signal configuration for each of the one or more sub-bands.

Abstract: The apparatus may be a UE configured to transmit, to a base station, an indication of a UE capability associated with a contiguous FD pilot; receive, from the base station, an indication of an allocation of one or more frequency sub-bands for a reception of one or more contiguous FD pilots; and receive, from the base station, the one or more contiguous FD pilots via the one or more frequency sub-bands. The apparatus may be a configured to receive, from a UE, an indication of a UE capability associated with a contiguous FD pilot; select one or more frequency sub-bands for a transmission of a contiguous FD pilot; transmit, to the UE, an indication of an allocation of the one or more frequency sub-bands for the transmission of the contiguous FD pilot; and transmit, to the UE, the contiguous FD pilot via the one or more frequency sub-bands.

Abstract: Certain aspects of the present disclosure provide techniques for network assisted selection of UE antenna ports for uplink transmissions. A method for wireless communication by a user equipment (UE) includes transmitting, to a network entity, a plurality of sounding reference signals over a plurality of UE antenna ports. The method further includes receiving, from the network entity, an indication of one or more antenna port indexes associated with one or more preferred antenna ports for uplink transmissions, and transmitting UE uplink transmissions to the network entity using one or more selected antenna ports of the one or more indicated preferred antenna ports.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive, from a second UE and using a first fast Fourier transform (FFT) window configuration, a physical sidelink control channel (PSCCH) signal associated with a physical sidelink shared channel (PSSCH) signal. The UE may identify, based at least in part on the reception of the PSCCH signal, one or more values of one or more parameters estimated from the PSCCH signal. The UE may select, based at least in part on the one or more values of the one or more parameters, a second FFT window configuration to be used to receive the PSSCH signal. The UE may receive, from the second UE, the PSSCH signal using the second FFT window configuration, Numerous other aspects are described.

Abstract: Disclosed are techniques for wireless communication. In some aspects, a base station (BS) may determine a first planned transmit beam configuration of the first BS. The BS may obtain a second planned transmit beam configuration of a second BS. The BS may determine that a first planned transmit beam of the first planned transmit beam configuration will interfere with a second planned transmit beam of the second planned transmit beam configuration. The BS may modify the first planned transmit beam, the second planned transmit beam, or both, based on the interference determination.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a network entity, a demodulation reference signal (DMRS) configuration indicating an intra-slot DMRS pattern. The UE may receive, from the network entity, an indication of an inter-slot DMRS pattern. The UE may communicate, with the network entity, a message that is associated with a time domain resource allocation that includes multiple slots, the message including one or more DMRSs in accordance with the intra-slot DMRS pattern and the inter-slot DMRS pattern. Numerous other aspects are provided.

Abstract: A base station may receive from a user equipment (UE) a proactive notification that the UE will perform a beam switch from a first UE beam to a second UE beam. In response, the base station may determine a beam switch slot on which the UE will perform the synchronized beam switch, and perform a link transient mitigation operation for communications with the UE after UE beam switch and until updating channel state information associated with a new UE beam. The base station may then receive from the UE channel state information feedback for a channel associated with the second UE beam, and adjust downlink data transmission parameters to be aligned with the second UE beam based on the received channel state information feedback (CSF). The base station may also adjust uplink data transmission parameters based on a sounding reference signal transmitted by the UE over the second UE beam.

Abstract: Aspects of the techniques and apparatuses described herein provide an intra slot antenna diversity scheme that a user equipment (UE) may use to transmit uplink communications while mitigating antenna imbalance. In an intra slot antenna diversity scheme, a UE transmits an uplink communication by transmitting a first portion of the uplink transmission in a first part of a slot using a first subset of antennas and a second portion of the uplink communication in a second part of the slot using a second subset of antennas. A decision to apply an intra slot antenna diversity scheme may be made by a network node such as a base station. Numerous other aspects are described.